In order to allow a semiconductor device such as a metal oxide semiconductor field effect transistor (MOSFET) to be high in breakdown voltage and low in loss and to be used in a high-temperature environment, silicon carbide has recently increasingly been adopted as a material forming a semiconductor device. Silicon carbide is a wide band gap semiconductor greater in band gap than silicon which has conventionally widely been used as a material forming a semiconductor device. Therefore, by adopting silicon carbide as a material forming a semiconductor device, a higher breakdown voltage and a lower on-resistance of a semiconductor device can be achieved. A semiconductor device in which silicon carbide has been adopted as a material is also advantageous in that lowering in characteristics during use in a high-temperature environment is less than in a semiconductor device in which silicon has been adopted as a material.
For example, Japanese Utility Model Laying-Open No. 4-34732 (PTD 1) describes an apparatus for annealing a wafer. With the apparatus for manufacturing by annealing of a wafer, a GaAs wafer is annealed, with a ring-shaped cover over the GaAs wafer being provided to cover only an outer circumferential portion of the GaAs wafer having a diameter of 76 mm.
S. J. Pearton and R. Caruso, “Rapid thermal annealing of GaAs in a graphite susceptor-comparison with proximity annealing,” J. Appl. Phys. 66 (2), 15 Jul. 1989, page 663-665 (NPD 1) describes a method of rapid thermal annealing, with a GaAs substrate being arranged in a susceptor made of graphite. According to the rapid thermal annealing method, a GaAs substrate is annealed, with a graphite cap being arranged above the GaAs substrate having a diameter of 2 inches (approximately 50 mm).